CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
ASSETS:
Securities held-to-maturity, fair value	$ 3,267	$ 4,041
STOCKHOLDERS’ EQUITY:
Preferred stock, par value (in dollars per share)	$ 25.00	$ 25.00
Preferred stock, authorized (in shares)	100,000,000	100,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, issued (in shares)	567,752,493	566,819,863
Common stock, outstanding (in shares)	461,116,723	466,007,984
Treasury stock (in shares)	106,635,770	100,811,879
Available-for-sale Securities
ASSETS:
Securities, pledged to creditors	$ 423	$ 363
Held-to-maturity Securities
ASSETS:
Securities held-to-maturity, fair value	$ 3,267	$ 4,041